Higher Glutathione Levels Research Articles

Abstract IA20: Lymph protects metastasizing melanoma cells from ferroptosis

Abstract Cancer cells, including melanoma, often metastasize regionally through lymphatics before metastasizing systemically through the blood; however, the reason for this is unclear. We discovered that melanoma cells in lymph experience less oxidative stress and form more metastases than melanoma cells in blood. Immunocompromised mice with patient-derived melanomas and immunocompetent mice with mouse melanomas had more melanoma cells per microliter of tumor-draining lymph than tumor-draining blood. Cells metastasizing through blood, but not lymph, became dependent on the ferroptosis inhibitor GPX4. Cells pre-treated with chemical ferroptosis inhibitors formed more metastases than untreated cells after intravenous, but not intralymphatic, injection. We observed multiple differences between lymph fluid and blood plasma that may contribute to decreased oxidative stress and ferroptosis in lymph, including higher levels of glutathione and oleic acid, and less free iron, in lymph. Oleic acid protected melanoma cells from ferroptosis in an Acsl3-dependent manner and increased their capacity to form metastatic tumors. Melanoma cells from lymph nodes were more resistant to ferroptosis and formed more metastases after intravenous injection than melanoma cells from subcutaneous tumors. Exposure to the lymphatic environment thus protects melanoma cells from ferroptosis and increases their ability to survive during subsequent metastasis through the blood. Citation Format: Sean J. Morrison. Lymph protects metastasizing melanoma cells from ferroptosis [abstract]. In: Abstracts: AACR Special Virtual Conference on Epigenetics and Metabolism; October 15-16, 2020; 2020 Oct 15-16. Philadelphia (PA): AACR; Cancer Res 2020;80(23 Suppl):Abstract nr IA20.

Immunogenic-cell-killing and immunosuppression-inhibiting nanomedicine

Combining chemo-therapeutics with immune checkpoint inhibitors facilitates killing cancer cells and activating the immune system through inhibiting immune escape. However, their treatment effects remain limited due to the compromised accumulation of both drugs and inhibitors in certain tumor tissues. Herein, a new poly (acrylamide-co-acrylonitrile-co-vinylimidazole-co-bis(2-methacryloyl) oxyethyl disulfide) (PAAVB) polymer-based intelligent platform with controllable upper critical solution temperature (UCST) was used for the simultaneous delivery of paclitaxel (PTX) and curcumin (CUR). Additionally, a hyaluronic acid (HA) layer was coated on the surface of PAAVB NPs to target the CD44-overexpressed tumor cells. The proposed nanomedicine demonstrated a gratifying accumulation in tumor tissue and uptake by cancer cells. Then, the acidic microenvironment and high level of glutathione (GSH) in cancer cells could spontaneously decrease the UCST of polymer, leading to the disassembly of the NPs and rapid drug release at body temperature without extra-stimuli. Significantly, the released PTX and CUR could induce the immunogenic cell death (ICD) to promote adaptive anti-tumor immunogenicity and inhibit immunosuppression through suppressing the activity of indoleamine 2,3-dioxygenase 1 (IDO1) enzyme respectively. Therefore, the synergism of this intelligent nanomedicine can suppress primary breast tumor growth and inhibit their lung metastasis.

Tumor Microenvironment-Responsive Fe(III)-Porphyrin Nanotheranostics for Tumor Imaging and Targeted Chemodynamic-Photodynamic Therapy.

The development of effective and safe tumor nanotheranostics remains a research imperative. Herein, tumor microenvironment (TME)-responsive Fe(III)-porphyrin (TCPP) coordination nanoparticles (FT@HA NPs) were prepared using a simple one-pot method followed by modification with hyaluronic acid (HA). FT@HA NPs specifically accumulated in CD44 receptor-overexpressed tumor tissues through the targeting property of HA and upon endocytosis by tumor cells. After cell internalization, intracellular acidic microenvironments and high levels of glutathione (GSH) triggered the rapid decomposition of FT@HA NPs to release free TCPP molecules and Fe(III) ions. The released Fe(III) ions could trigger GSH depletion and Fenton reaction, activating chemodynamic therapy (CDT). Meanwhile, the fluorescence and photodynamic effects of the TCPP could be also activated, achieving controlled reactive oxygen species (ROS) generation and avoiding side effects on normal tissues. Moreover, the rapid consumption of GSH further enhanced the efficacy of CDT and photodynamic therapy (PDT). The in vivo experiments further demonstrated that the antitumor effect of these nanotheranostics was significantly enhanced and that their toxicity and side effects against normal tissues were effectively suppressed. The FT@HA NPs can be applied for activated tumor combination therapy under the guidance of dual-mode imaging including fluorescence imaging and magnetic resonance imaging, providing an effective strategy for the design and preparation of TME-responsive multifunctional nanotheranostics for precise tumor imaging and combination therapy.

Aldh1l2 knockout mouse metabolomics links the loss of the mitochondrial folate enzyme to deregulation of a lipid metabolism observed in rare human disorder

BackgroundMitochondrial folate enzyme ALDH1L2 (aldehyde dehydrogenase 1 family member L2) converts 10-formyltetrahydrofolate to tetrahydrofolate and CO2 simultaneously producing NADPH. We have recently reported that the lack of the enzyme due to compound heterozygous mutations was associated with neuro-ichthyotic syndrome in a male patient. Here, we address the role of ALDH1L2 in cellular metabolism and highlight the mechanism by which the enzyme regulates lipid oxidation.MethodsWe generated Aldh1l2 knockout (KO) mouse model, characterized its phenotype, tissue histology, and levels of reduced folate pools and applied untargeted metabolomics to determine metabolic changes in the liver, pancreas, and plasma caused by the enzyme loss. We have also used NanoString Mouse Inflammation V2 Code Set to analyze inflammatory gene expression and evaluate the role of ALDH1L2 in the regulation of inflammatory pathways.ResultsBoth male and female Aldh1l2 KO mice were viable and did not show an apparent phenotype. However, H&E and Oil Red O staining revealed the accumulation of lipid vesicles localized between the central veins and portal triads in the liver of Aldh1l2-/- male mice indicating abnormal lipid metabolism. The metabolomic analysis showed vastly changed metabotypes in the liver and plasma in these mice suggesting channeling of fatty acids away from β-oxidation. Specifically, drastically increased plasma acylcarnitine and acylglycine conjugates were indicative of impaired β-oxidation in the liver. Our metabolomics data further showed that mechanistically, the regulation of lipid metabolism by ALDH1L2 is linked to coenzyme A biosynthesis through the following steps. ALDH1L2 enables sufficient NADPH production in mitochondria to maintain high levels of glutathione, which in turn is required to support high levels of cysteine, the coenzyme A precursor. As the final outcome, the deregulation of lipid metabolism due to ALDH1L2 loss led to decreased ATP levels in mitochondria.ConclusionsThe ALDH1L2 function is important for CoA-dependent pathways including β-oxidation, TCA cycle, and bile acid biosynthesis. The role of ALDH1L2 in the lipid metabolism explains why the loss of this enzyme is associated with neuro-cutaneous diseases. On a broader scale, our study links folate metabolism to the regulation of lipid homeostasis and the energy balance in the cell.

Near-Infrared-Controlled Nanoplatform Exploiting Photothermal Promotion of Peroxidase-like and OXD-like Activities for Potent Antibacterial and Anti-biofilm Therapies.

Nanozymes that mimic peroxidase (POD) activity can convert H2O2 into bactericidal free radicals, which is referred to as chemodynamic therapy (CDT). High glutathione (GSH) levels in the infectious tissue severely limit the performance of CDT. Herein, we report a near-infrared-controlled antibacterial nanoplatform that is based on encapsulating tungsten sulfide quantum dots (WS2QDs) and the antibiotic vancomycin in a thermal-sensitive liposome. The system exploits the photothermal sensitivity of the WS2QDs to achieve selective liposome rupture for the targeted drug delivery. We determined that WS2QDs show a strong POD-like activity under physiological conditions and the oxidase-like activity, which can oxidate GSH to further improve the CDT efficacy. Moreover, we found that increased temperature promotes multiple enzyme-mimicking activities of WS2QDs. This platform exerts antibacterial effects against Gram-positive Mu50 (a vancomycin-intermediate Staphylococcus aureus reference strain) and Gram-negative Escherichia coli and disrupts biofilms for improved penetration of therapeutic agents inside biofilms. In vivo studies with mice bearing Mu50-caused skin abscess revealed that this platform confers potent antibacterial activity without obvious toxicity. Accordingly, our work illustrates that the photothermal and nanozyme properties of WS2QDs can be deployed alongside a conventional therapeutic to achieve synergistic chemodynamic/photothermal/pharmaco therapy for powerful antibacterial effects.

Synthesis, self-assembly and anticancer drug encapsulation and delivery properties of cyclodextrin-based giant amphiphiles

Cyclodextrin-calixarene giant amphiphiles that can self-assemble into nanospheres or nanovesicles have the ability to encapsulate the anticancer hydrophobic drugs docetaxel, temozolomide and combretastatin A-4 with encapsulation efficiencies >80% and deliver them to tumoral cells, enhancing their therapeutic efficacy by 1-3 orders of magnitude. These amphiphiles were modified by inserting a disulfide bridge confering them redox responsiveness. Disassembly of the resulting nanocompounds and cargo release was favored by high glutathione levels mimicking those present in the tumor microenvironment. Anticancer drug-loaded nanoformulations inhibited prostate, breast, glioblastoma, colon or cervix cancer cell lines proliferation with IC50 values markedly below those observed for the free drugs. Cell-cycle analysis indicated a similar mechanism of action for drug-loaded nanocompounds and free drugs. The results strongly suggest that the cyclodextrin-calixarene heterodimer prototype is an excellent scaffold for nanoformulations aimed to deliver anticancer drugs with limited bioavailability due to low solubility to tumoral cells, markedly increasing their effectivity.

Liproxstatin-1 is an effective inhibitor of oligodendrocyte ferroptosis induced by inhibition of glutathione peroxidase 4

Our previous studies showed that ferroptosis plays an important role in the acute and subacute stages of spinal cord injury. High intracellular iron levels and low glutathione levels make oligodendrocytes vulnerable to cell death after central nervous system trauma. In this study, we established an oligodendrocyte (OLN-93 cell line) model of ferroptosis induced by RSL-3, an inhibitor of glutathione peroxidase 4 (GPX4). RSL-3 significantly increased intracellular concentrations of reactive oxygen species and malondialdehyde. RSL-3 also inhibited the main anti-ferroptosis pathway, i.e., SLC7A11/glutathione/glutathione peroxidase 4 (xCT/GSH/GPX4), and downregulated acyl-coenzyme A synthetase long chain family member 4. Furthermore, we evaluated the ability of several compounds to rescue oligodendrocytes from ferroptosis. Liproxstatin-1 was more potent than edaravone or deferoxamine. Liproxstatin-1 not only inhibited mitochondrial lipid peroxidation, but also restored the expression of GSH, GPX4 and ferroptosis suppressor protein 1. These findings suggest that GPX4 inhibition induces ferroptosis in oligodendrocytes, and that liproxstatin-1 is a potent inhibitor of ferroptosis. Therefore, liproxstatin-1 may be a promising drug for the treatment of central nervous system diseases.

Photothermal Generation of Oxygen-Irrelevant Free Radicals with Simultaneous Suppression of Glutathione Synthesis for an Enhanced Photonic Thermodynamic Cancer Therapy.

Reactive oxygen species (ROS) as one kind of oxygen-dependent toxic free radical has been widely adopted in ROS-mediated therapies (RMT). However, two shackles, known as tumor hypoxia and high intratumor glutathione (GSH) levels, respectively, limit RMT as the former prevents ROS from generating, while the latter scavenges the ROS generated. Herein, we developed a novel nanoplatform to simultaneously overcome the two shackles by facile preparation of mesoporous carbon nanospheres (MCNs) with AIBI and raloxifene loaded inside as an initiator and inhibitor, respectively, and phase-change materials (PCMs) capped outside as gatekeepers. Upon 808 nm NIR light irradiation, the photothermal effect of MCNs melted PCMs causing the loaded AIBI and raloxifene to be released, during which the AIBI was further decomposed into oxygen-irrelevant radicals to kill cancer cells, while the raloxifene suppressed GSH synthesis, synergistically enabling an enhanced photonic thermodynamic cancer therapy.

Internal cross-linked polymeric nanoparticles with dual sensitivity for combination therapy of muscle-invasive bladder cancer

BackgroundChemotherapy is a standard cancer treatment which uses anti-cancer drugs to destroy or slow the growth of cancer cells. However, chemotherapy has limited therapeutic effects in bladder cancer. One of the reasons of this resistance to chemotherapy is that higher levels of glutathione in invasive bladder cancer cells. We have fabricated nanoparticles that respond to high concentrations of glutathione and near-infrared laser irradiation in order to increase the drug accumulation at the tumor sites and combine chemotherapy with photothermal therapy to overcome the challenges of bladder cancer treatment.MethodsThe DOX&IR780@PEG-PCL-SS NPs were prepared by co-precipitation method. We investigated the tumor targeting capability of NPs in vitro and in vivo. The orthotopic bladder cancer model in C57BL/6 mice was established for in vivo study and the photothermal effects and therapeutic efficacy of NPs were evaluated.ResultsThe DOX&IR780@PEG-PCL-SS NPs were synthesized using internal cross-linking strategy to increase the stability of nanoparticles. Nanoparticles can be ingested by tumor cells in a short time. The DOX&IR780@PEG-PCL-SS NPs have dual sensitivity to high levels of glutathione in bladder cancer cells and near-infrared laser irradiation. Glutathione triggers chemical structural changes of nanoparticles and preliminarily releases drugs, Near-infrared laser irradiation can promote the complete release of the drugs from the nanoparticles and induce a photothermal effect, leading to destroying the tumor cells. Given the excellent tumor-targeting ability and negligible toxicity to normal tissue, DOX&IR780@PEG-PCL-SS NPs can greatly increase the concentration of the anti-cancer drugs in tumor cells. The mice treated with DOX&IR780@PEG-PCL-SS NPs have a significant reduction in tumor volume. The DOX&IR780@PEG-PCL-SS NPs can be tracked by in vivo imaging system and have good tumor targeting ability, to facilitate our assessment during the experiment.ConclusionA nanoparticle delivery system with dual sensitivity to glutathione and near-infrared laser irradiation was developed for delivering IR780 and DOX. Chemo-photothermal synergistic therapy of both primary bladder cancer and their metastases was achieved using this advanced delivery system.

Metabolic response of the Siberian wood frog Rana amurensis to extreme hypoxia

The Siberian wood frog Rana amurensis is a recently discovered example of extreme hypoxia tolerance that is able to survive several months without oxygen. We studied metabolomic profiles of heart and liver of R. amurensis exposed to 17 days of extreme hypoxia. Without oxygen, the studied tissues experience considerable stress with a drastic decrease of ATP, phosphocreatine, and NAD+ concentrations, and concomitant increase of AMP, creatine, and NADH. Heart and liver switch to different pathways of glycolysis with differential accumulation of lactate, alanine, succinate, as well as 2,3-butanediol (previously not reported for vertebrates as an end product of glycolysis) and depletion of aspartate. We also observed statistically significant changes in concentrations of certain osmolytes and choline-related compounds. Low succinate/fumarate ratio and high glutathione levels indicate adaptations to reoxygenation stress. Our data suggest that maintenance of the ATP/ADP pool is not required for survival of R. amurensis, in contrast to anoxia-tolerant turtles.

LED light-triggered release of nitric oxide from NTC to delay the ripening of banana

Effect of nitric oxide released from nitrate trimethylolethane cyclocarbonate (NTC) by LED triggered on banana quality was studied. Banana was coated with the combination of 1 mM NTC and 1.5% (w/v) sodium alginate. The characteristic changes of banana stored at 25 °C and 70% humidity for 15 days were studied. The results showed that nitric oxide released continuously from NTC for 12 days under the LED light stimulation. RAW cell maintained 90% viability after incubation with NTC. The preservation results indicated the NTC treatment with the exposure of LED light effectively prolonged the yellowing time of banana, inhibited the chlorophyll degradation, the accumulation of reducing sugar and MDA, maintained high level of phenolics, ascorbic acid and glutathione in antioxidant system of banana, enhanced SOD activity, which were not observed in the controls. This work implied that the ripening of banana could be delayed or even controlled by LED light.

Effects of arbuscular mycorrhizal fungi on redox homeostasis of rice under Cd stress

Arbuscular mycorrhizal fungi (AMF) can enhance cadmium (Cd) tolerance and decrease Cd uptake of rice plant. However, in these processes, the essential role of reactive oxygen species (ROS)-antioxidants interactions is so far not investigated. We inoculated AMF, Funneliformis mosseae (Fm) and Rhizophagus intraradices (Ri), to upland rice subjected to 0, 2 or 10 mg Cd kg−1 in soil. ROS, antioxidants, chlorophyll, mesophyll cell ultrastructure, Cd concentration and Cd transporters were measured. Results showed that the levels of ROS (i.e., superoxide, hydrogen peroxide and lipid peroxidation) were mitigated in +AMF + Cd treatments, especially in +Ri + Cd, compared with −AMF + Cd. For antioxidants, lower levels of catalase, peroxidase and superoxide dismutase, whereas higher levels of glutathione and glutathione peroxidase were observed in +AMF + Cd compared with −AMF + Cd. Chlorophyll content and mesophyll cell ultrastructure were improved by AMF. Cd concentrations in plants were significantly decreased in +AMF + Cd (10 mg Cd kg−1) treatments. AMF not only decreased Cd accumulation in rice but also regulated the ROS scavenging activities. The variations of ROS and antioxidants were restrained to smaller ranges by AMF. AMF may assist in Cd restriction and thus helping the host to release glutathione for ROS scavenging.

Tumor‐Microenvironment‐Activated In Situ Self‐Assembly of Sequentially Responsive Biopolymer for Targeted Photodynamic Therapy

AbstractA sequentially responsive photosensitizer‐integrated biopolymer is developed for tumor‐specific photodynamic therapy, which is capable of forming long‐retained aggregates in situ inside tumor tissues. Specifically, the photosensitizer zinc phthalocyanine (ZnPc) is conjugated with polyethylene glycol (PEG) via pH‐labile maleic acid amide linker and then immobilized onto the hyaluronic acid (HA) chain using a redox‐cleavable disulfide linker. The PEG segment can enhance blood circulation of the molecular carrier after intravenous administration and be shed after reaching the acidic tumor microenvironment, allowing the remaining fragment to self‐assemble into large clusters in situ to avoid backward diffusion and improve tumor retention. This process is driven by hydrophobic interactions and does not require additional external actuation. The aggregates are then internalized by the tumor cells via HA‐facilitated endocytosis, and the high glutathione level in tumor cells eventually leads to the intracellular release of ZnPc to facilitate its interaction with the subcellular lipid structures. This tumor‐triggered morphology‐based delivery platform is constructed with clinically tested components and could potentially be applied to other hydrophobic therapeutics.

Redox responsive paclitaxel dimer for programmed drug release and selectively killing cancer cells

Redox stimulus responsive drug delivery systems have been widely investigated and proved to be promising prospects for efficient cancer therapy due to the abnormal high level of reactive oxygen species and glutathione in tumor microenvironment. Herein, three paclitaxel dimers (named as PTX2-R, R = S, Se and Te) bridged with alkyl sulfide, selenide or telluride are synthesized. These dimers can self-assemble into stable uniform nanoparticles (named as PTX2-R NPs, R = S, Se and Te) with impressively high drug loading. As expected, sulfur/selenium/tellurium bonds exhibit different redox responsiveness, thereby affecting the drug release and cytotoxicity. Of note, tellurium bridged paclitaxel dimer shows ultra-sensitivity to hydrogen peroxide, which rapidly cleaves into two paclitaxel under the subsequent dithiothreitol stimulation. Our findings provide deep insight into the redox sensitivity of chalcogenide elements and offer the rational design strategies to biologically redox condition for programmed drug release.

Specific-oxygen-supply functionalized core-shell nanoparticles for smart mutual-promotion between photodynamic therapy and gambogic acid-induced chemotherapy

Photodynamic therapy (PDT) and chemotherapy of cancer both meet respective challenges. Tumor hypoxia, low penetration and high glutathione (GSH) level bear the brunt. Herein, a core-shell nanoparticle, with multi-function of hypoxia-responsiveness, specific oxygen supply and deep tumor penetration, was constructed for smart mutual-promotion between the both to overcome the respective restrictions. The nano platform (GC@MCS NPs) was composed of hypoxia-responsive hyaluronic acid-nitroimidazole (HA-NI) as shells, MnO2 NPs as oxygen modulators and reduction-responsive functionalized poly (l-glutamic acid) derivatives (γ-PFGA) as cores to deliver gambogic acid (GA) and Chlorine6 (Ce6). After endocytosis, the approximately 100 nm of GC@MCS NPs achieved hypoxia-responsive shell degradation and MnO2 release, followed by reduction-activated charge conversion to form positively charged cores. With the damage effect of superficial tumor cells by the partially released GA, GA&Ce6-loadedγ-PFGA penetrated deep inside through electronic interaction step by step. Upon irradiated with 638 nm of laser, widely permeated Ce6 was activated for enhanced PDT under the high oxygenation by MnO2 NPs. The generated reactive oxygen species (ROS) in return facilitated the GA-induced paraptosis by clearing high level of GSH. As a result, this mutual promotion strategy contributed to 92.41% of 4T1 tumor inhibition rate, exhibiting outstanding advantages. Our GC@MCS NPs provided a smart combination of chemo-photodynamic therapy and focused on addressing the tumor hypoxia and low penetration issues.

Basal catalase activity and high glutathione levels influence the performance of non-Saccharomyces active dry wine yeasts

Non-Saccharomyces wine yeasts are useful tools for producing wines with complex aromas or low ethanol content. Their use in wine would benefit from their production as active dry yeast (ADY) starters to be used as co-inocula alongside S. cerevisiae. Oxidative stress during biomass propagation and dehydration is a key factor in determining ADY performance, as it affects yeast vitality and viability. Several studies have analysed the response of S. cerevisiae to oxidative stress under dehydration conditions, but not so many deal with non-conventional yeasts. In this work, we analysed eight non-Saccharomyces wine yeasts under biomass production conditions and studied oxidative stress parameters and lipid composition. The results revealed wide variability among species in their technological performance during ADY production. Also, for Metschnikowia pulcherrima and Starmerella bacillaris, better performance correlates with high catalase activity and glutathione levels. Our data suggest that non-Saccharomyces wine yeasts with an enhanced oxidative stress response are better suited to grow under ADY production conditions.

Redox-responsive AIE micelles for intracellular paclitaxel delivery

Compared with conventional drug nanocarriers, multifunctional drug delivery systems exhibited characteristic advantages. In this study, we developed a multifunctional drug delivery system possessing stimuli-responsive drug release and cellular imaging. Amphiphilic polymers, methoxypolyethylene glycol-cystamine-tetraphenylethene (mPEG1k-SS-TPE), were synthesized by combining methoxypolyethylene glycol (mPEG1k) and tetraphenylethene (TPE) using reduction-sensitive disulfide bonds that can be disconnected by high level of inherent glutathione (GSH). Size distribution and morphology of mPEG1k-SS-TPE micelles were evaluated. Meanwhile, the reduction-sensitivity of mPEG1k-SS-TPE micelles was surveyed compared with that of mPEG1k-TPE micelles. Nile Red was encapsulated into mPEG1k-SS-TPE micelles to visually observe intracellular drug delivery against SW480 cells. Paclitaxel (PTX) was chosen to be loaded into micelles to evaluate the cytotoxicity against HCT116, HT-29, and SW480.

Engineering a pH/Glutathione-Responsive Tea Polyphenol Nanodevice as an Apoptosis/Ferroptosis-Inducing Agent.

Chemotherapy works against tumors by inducing cell apoptosis; however, evasion of apoptosis is recognized to result in resistance to anticancer therapy. Ferroptosis is an iron-dependent cell death pathway that differs from apoptosis in morphological, biochemical, and genetic levels. Combined ferroptosis and apoptosis may shed light on strategies for cancer treatment. Therefore, we have designed a nanoparticle (NP) that can simultaneously cause tumor cell apoptosis and ferroptosis. This NP is composed of epigallocatechin gallate (EGCG) and Fe3+ through a simple and green process and can be used to deliver doxorubicin hydrochloride (DOX) and iron ions to the tumor site at the same time. DOX/Fe3+/EGCG (DF) NPs display a great resolubility and long-term storage stability, and efficient DOX and Fe3+ release is realized after cellular internalization under the high level of glutathione and acidic nature in tumor. EGCG is likely to chemically reduce the released Fe3+ to Fe2+. The generated Fe3+/Fe2+ converts intracellular H2O2 to hydroxyl radicals (•OH) via the Fenton reaction. In addition, the generated •OH subsequently induces lethal ferroptosis to improve DOX-induced apoptosis. In vitro and in vivo investigations indicate that a great therapeutic effect was achieved, suggesting that the formation of the DF NP delivery system is a promising strategy to fight against tumors by an apoptosis and ferroptosis combination modality.

Oxidative Stress and Its Association with COVID-19: A Narrative Review

The naturalness of severe acute respiratory syndrome coronavirus 2 infections (SARS-Cov-2) appears to impact the respiratory system and lungs, however, the etiology of many cases exhibited several various features of the disease. The Coronavirus disease 2019 (COVID-19) symptoms are not limited to the virus’s first definitions. This review gathered the contemporary information throughout PubMed, Scopus, and Science Direct databases regarding possible effects of the virus in generating reactive oxygen species and causing oxidative stress. However, this ensures a hypothesis for now, yet from the literature and incidence of COVID-19 symptoms along with comorbidities we can observe the potentials of the virus in the generation of oxidative stress. Especially the virus’s route to cell entry via angiotensin-converting enzyme 2 (ACE2) receptor is well known that leads to pathogenesis in angiotensin II (AT II) which are critical in NADH/NADPH oxidase inducing ROS generation. Moreover, the virus’s activity to replicate seems to be reduced in high antioxidant glutathione level concentrations. The outcome of the review proposes a hypothesis that COVID-19 is associated with reactive oxygen species and its comorbidities mostly joined with oxidative stress including hypertension, cardiovascular, thrombosis, obesity, and diabetes besides of chronic obstructive pulmonary disease and asthma.

Astrocyte glutathione maintains endothelial barrier stability

Blood-brain barrier (BBB) impairment clearly accelerates brain disease progression. As ways to prevent injury-induced barrier dysfunction remain elusive, better understanding of how BBB cells interact and modulate barrier integrity is needed. Our metabolomic profiling study showed that cell-specific adaptation to injury correlates well with metabolic reprogramming at the BBB. In particular we noted that primary astrocytes (AC) contain comparatively high levels of glutathione (GSH)-related metabolites compared to primary endothelial cells (EC). Injury significantly disturbed redox balance in EC but not AC motivating us to assess 1) whether an AC-EC GSH shuttle supports barrier stability and 2) the impact of GSH on EC function. Using an isotopic labeling/tracking approach combined with Time-of-Flight Mass Spectrometry (TOF-MS) we prove that AC constantly shuttle GSH to EC even under resting conditions - a flux accelerated by injury conditions in vitro. In correlation, co-culture studies revealed that blocking AC GSH generation and secretion via siRNA-mediated γ-glutamyl cysteine ligase (GCL) knockdown significantly compromises EC barrier integrity. Using different GSH donors, we further show that exogenous GSH supplementation improves barrier function by maintaining organization of tight junction proteins and preventing injury-induced tight junction phosphorylation. Thus the AC GSH shuttle is key for maintaining EC redox homeostasis and BBB stability suggesting GSH supplementation could improve recovery after brain injury.